bondage vs feudalism

bondage

noun
  • The state of lacking freedom; constraint. 

  • The state of being enslaved or the practice of slavery. 

  • The practice of physically restraining people for sexual pleasure, such as by tying up or shackling. 

  • Applied to clothing with many buckles, zips, etc., associated with punk and goth subcultures. 

feudalism

noun
  • A social system based on personal ownership of resources and personal fealty between a suzerain (lord) and a vassal (subject). Defining characteristics are direct ownership of resources, personal loyalty, and a hierarchical social structure reinforced by religion. 

How often have the words bondage and feudalism occurred in a corpus of books? (source: Google Ngram Viewer )